A major misconception is that it's all basically Type 2. Articles will frequently be discussing Type 2, but simply refer to it as "Diabetes", and say things which are completely inapplicable to Type 1. But many journalists are in that field because things like biology didn't really pan out for them in school, so it's very rare for one to understand anything medical. Naturally the message they pass along contains a fair bit of gibberish as a result.
Another misconception is that Type 2 is usually, or only, caused by sitting around and over-eating. I'm forced to do the sitting around due to being disabled by a chronic illness, but the only advice I've gotten from nutritionists, both before and after developing diabetes, is that I should be eating more bread. And there's plenty of people who were skinny and active when developing Type 2. Does being overweight contribute to Type 2? Quite possibly. Does it cause Type 2? Definitely not, or the skinny/active cases simply would not happen.
My final peeve would be the misconception that Type 2 isn't chronic or serious. It's often being presented as something caused by being overweight, and presumably cured by losing a little weight and going for walks. But the reality is that even previously overweight Type 2s still can't eat a normal diet, or even stop meds sometimes, even though they've lost all the extra weight and are running marathons now.